Preparation of photographic direct positive color images and photographic elements therefor



Oct. 17, 1967 w. M. SALMINEN 3,347,671

PREPARATION OF PHOTOGRAPHIC DIRECT POSITIVE COLOR IMAGES AND PHOTOGRAPHIC ELEMENTS THEREFOR Filed Sept. 20, 1963 UGHT-SENSITIVE EMULSION LAYER CONTAIN/N6 DIFFUSIBLE DYE- RELEASING COUPLER I SU PPORT SUPPORT MORDANT LAYER RUPTURABLE POD CONTAINING 2'7 PROCESSING COMPOSITION 26 TOPCOAT LAYER BLUE-SENSITIVE EMULSION LAYER CONTAINING DIFFUSIBLE YELLOWDYE- RELEASING COUPLER INTERLAYER GREEN-SENSITIVE EMULSION LAYER CONTAINING DlFFUS/BLE MAGEN'IZI DYE- RELEASING COUPLER INTERLAYER RED-SENSITIVE EMULSION LAYER CONTAINING DIEFUS/BLE CYAN DYE- RELEASING COUPLER SUPPORT Figz \Vilho M .Salminen IN VENTOR.

United States Patent PREPARATION OF PHOTOGRAPHIC DIRECT POSI- TIVE- COLOR IMAGES AND PHQTOGRAPHIC ELEMENTS THEREFOR Wiiho M. Saiminen, Rochester, N.Y., assignor to Eastman Kodak (Zompany, Rochester, N.Y., a corporation of New Jersey Filed Sept. 20, 1963, Ser. No. 310,424 20 Claims. (Cl. 963) The present invention relates to color photography, and more particularly, to photographic color diffusion transfer processes and photographic elements suitable for use in such processes.

Useful photographic color diffusion transfer processes for preparing direct positive color images are described in British Patents 840,731 and 904,364. In such processes, direct positive silver halide emulsions having silver halide grains with substantial internal sensitivity of the type described in Davey et al., US. Patent 2,592,250 are desirably utilized. In such processes, the photographic element containing a Davey et a1. internal latent image silver halide emulsion and a nondifiusible coupler that releases a diffusible dye on coupling with oxidized aromatic primary amino color developing agent is processed by treating the element in an alkaline processing medium in the presence of a color developing agent. Development occurs in the unexposed or positive image areas of the emulsions, resulting oxidized developing agent reacting with the color coupler in such areas to produce a positive dye image which thereafter is allowed to diffuse to a dye image reception layer.

Hydrazines of the type described in Ives US. Patents 2,563,785 and 2,588,982 and related fogging agents are used to facilitate the reversal effect obtainedwith internal latent image silver halide emulsions. However, hydrazines tend to be unstable. Also, hydrazines cause skin allergies and are thus undesirable addenda to handle during the manufacture and use of photographic products. It is thus desirableto have fogging agents for use with internal latent image silver halide emulsions that are not of the hydrazine type.

Aromatic primary amino color developing agentsof the type utilized in processing compositions used in such color diffusion transfer processes have a tendency to become unstable and deteriorate with time. It is highly desirable that the developing agents in such processing compositions have their stability substantially increased so that these processing compositions can be incorporated into rupturable containers such as pods integral with photographic elements of the type utilized for in-camera processing.

A good color saturation or dye density is desired in diffusion transfer processes. It is particularly'desirable in color diffusion transfer processes that the emulsion layers be relatively thin to aid in the reduction of the image transfer time. However, the emulsion layers must be of suflicient thickness to contain enough color coupling material to form transfer images having high color density. Hence, it is desirable to have a method for obtaining maximum of dye densities with the thinnest possible thickness of emulsion layers in color diffusion transfer processes.

It is an object of this invention to provide a new stable fogging agent for use in conjunction with silver halide emulsions that form latent images predominantly inside the silver halide grains when such emulsions are utilized in color diffusion transfer processes.

It is another object of this invention to provide a novel color developer stabilizing material suitable for use in conjunction with color diffusion transfer processes.

Ice Patented Oct. 17, 1967 It is another object of this invention to provide a new process for preparing direct positive color images having increased dye density.

It is another object of this invention to provide novel light-sensitive elements or films suitable for use in direct positive color diffusion transfer processes.

It is also an object of this invention to provide a novel color diffusion transfer process that can be effected in one wet processing step.

It is still another object of this invention to provide a novel photographic diffusion transfer process wherein a dye image of improved density is transferred to a receiving layer.

Thesegand other objects are attained by means of this invention as described hereinafter with reference to preferred embodiments thereof.

The present invention concerns the processing of photographic elements having superposed thereon at least one silver halide emulsion having substantial proportions of silver halide that form latent images predominantly inside the silver halide grains and a nondiffusible coupler that forms a diifusible dye on reaction with oxidized aromatic primary amino developing agent contiguous to the silver halide of the emulsion, said processing being carried out in the presence of a reductone derivative as described below. The silver halide emulsions utilized in the photographic or light-sensitive. elements of the invention are prepared with silver halide grains wherein a substantial amount, and preferably a predominant amount, of the sensitivity to light is internal to the grain. Such emulsions are to be distinguished from emulsions containing silver halide grains that form latent images on the surface thereof. Suitable silver halides include silver chloride, silver bro mide, silver bromoiodide, silver chloroiodide,and silver chlorobromoiodide. For a description of suitable emulsions that form latent images internal to the silver halide grains, reference is made to Davey et al., US. Patent 2,592,250; and Glafkides, Photographic Chemistry, volume 1, pages 31-2, Fountain Press, London. Typically such emulsions are those which, when measured according to normal photographic techniques by coating a test portion of the emulsion on a transparent support, exposing to a light intensity scale having a fixed time between 1 1'0- and 1 second, bleaching 5 minutes in a 0.3% potassium ferricyanide solution at 65 F. and developing for about 5 minutes at 65 F. in Developer B below (an internal-type? developer), have a sensitivity, measured at a density of 0.1 above fog, greater than the sensitivity of an identical test portion which has been exposed in the same way and developed for 6 minutes at 68 F. in Developer A below (a surface-type developer).

' Water to make 1 liter.

A wide variety of hydrophilic, water-permeable organic colloids. can be suitably utilized in preparing the silver halide emulsions or dispersions of the invention. Gelatin is preferably utilized although other colloidal material such as colloidal albumin,-cellulose derivatives, synthetic resins orthe like can be utilized. Suitable colloids that can be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe,.U.S. Patent 2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 1926% as described in US. Patent 2,327,808. of Lowe and Clark, issued August 24, 1943; a water-soluble ethanolamine cellulose acetate as described inYutzy, US. Patent 2,322,085, issued June 15, 1943; a polyacrylamide having a combined acrylamide content of 30-60% and a specific viscosity of 0.251.5 on an imidized polyacrylamide of like acrylamide content and viscosity as described in Lowe, Minsk and Kenyon, US. Patent 2,541,- 474 issued February 13, 1951; zein as described in Lowe, US. Patent 2,563,791, issued August 7, 1951; a vinyl alcohol polymer containing urethane carboxylic acid groups of'thetype described in Unruh and Smith, US. Patent 2,768,154, issued October 23, 1956; or containing cyano-acetyl groups such as the vinyl alcohol-vinyl cyanoacetate copolymer as described in Unruh, Smith and Priest, US. Patent 2,808,331, issued October 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a vinyl group, as. described in Illingsworth, Dann and Gates, US. Patent 2,852,382, issued September 19, 1958.

The subject photographic silver halide emulsions of the invention can contain the addenda generally utilized in such products including gelatin hardeners, gelatin plasticizers, coating aids, chemical sensitizers, optical sensitizers and the like.

The above-described emulsions of the invention can be coated on a wide variety of supports in accordance with usual practice. Typical supports for photographic elements of the invention include paper, polyethylene-coated paper, cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylenerterephthalate film and related films of resinous materials andothers.

The color couplers used in the photographic elements of the invention are ballasted andinitially nondilfusing in photographic silver halide emulsions but for-m difiusible dyes on development with aromatic primary amino silver halide photographic color developing agents such as pphenylenediamine color developing agents. The color couplersutilized in the invention possess a substituent in the coupling position which is displaceable upon coupling with oxidation products of color developing agents. Such color couplers can be referred to as DDR or diffusible dye releasing couplers and includethose having the formulas:

DYE-LIN K -(CO UP-- BALL) and BALL-LIN K(COUP--SOL) n wherein:

(1) DYE is a dye radical containing an acidic solubilizing radical; (2) LINK is a connecting or linkage radical such as azo (-N N), azoxy T mercuri (--Hg-), oxy (--O-), alkylidene (includes both wherein R is a hydrogen atom or an alkyl radical generally having 1 to 4 carbon atoms), thio (S-), or dithio (S -S);

(3) COUP is a photographic color coupler radical such as a S-pyrazolone coupler radical, a phenolic coupler radical or an open-chain ketomethylene coupler radical, the coupler radical being substituted in the coupling position with LINK;

(4) BALL is a photographically inert organic radical of such molecular size and configuration as to render the coupler nondiffusing in the alkaline color developing solution;

(5) SOL is either'a hydrogen atom or an acidic solubilizing group when the color developing agent contains: an acidic vsolubilizing radical, SOL always beingan acidic solubilizing radical when the color developing agent is free of an acidic solnbilizing group; and

(6) n is an integer of l to 2 whenLINK is an alkylidene radical, and n is always 1 when LINK is one of the other aforementioned connecting radicals, namely, azo, azoxy, mercuri, oxy, thio, or'dithio.

The acidic solubilizing radicals attached to the diffusible dye-producing couplers described above can be solubilizing radicals which when attached to the coupler or developer I coupler molecules as well as aromatic radicals of the benzene and naphthalene series, etc., linked directly or indi-- rectly to the coupler molecules by a splittable linkage, or

by a removable or irrernovable but otherwise nonfunc,

tional linkage depending upon the nature of the coupler compound. Useful ballast groupshave at least 8 carbon atoms.

Typical dye radical substituents (DYE-) include azo, azomethine,indoaniline, indophenol, anthraquinone and related dye radicals well known in the art that exhibit selective absorption in the visible spectrum. The dye radicals contain acidic solubilizing moieties.

With regard to the above-described coupler radicals.

(COUP), the coupling position is well known to those skilled in the photographic art. The 5-pyrazolone coupler radicals couple at the carbon atom in the 4position, the phenolic coupler radicals including a-naphthols, couple at the carbon atom in the 4-position and the openchain ketomethylene coupler radicals couple to the carbon atom forming the methylene moiety -(e.g.,

denoting the coupling position).

The term nondifiusing used herein as applied to the couplers, has the meaning commonly applied to the term in color photography and denotes materials which for all practical purposes do not migrate or wander through organic colloid layers, such as gelatin, comprising the sensitive elements of the invention in the presence of aqueous alkaline processing solution. The same meaning is to be attached to the term immobile.

The term diffusible as applied to the dyes formed from the nondiffusing couplers in the processes hasthe converse meaning and denotes materials having the property of diffusing effectively through the colloid layers of the sensitive elements in the presence of aqueous alkaline processing solution. Mobile has the same meaning.

When couplers having the formula DYELINK-(COUP-BALL) n as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a ditfusible preformed dye (DYE) is released which diffuses imagewise to a reception layer. An acidic solubilizing group on the preformed dye lends difiusibility to the dye molecule. The coupling portion of the coupler (COUP) couples with the color developing agent oxidation product to form a dye that is nondiffusible because of the attached ballasting group (BALL) in a noncoupling position. In this type of coupler, the color of the diifusible dye is determined by the color of the preformed dye moiety (DYE), the color of the reaction product of color developer oxidation product and the coupler moiety (COUP) being unimportant to the color of the difiusible image.

When couplers having the formula BALLLINK(COUPSOL) n as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a ditfusible dye is formed with the color developing agent oxidation product and the coupling portion (COUP) of the coupler which difiuses imagewise to a reception layer. Diifusibility is imparted to the dye by an acidic solubilizing group attached to a noncoupling position of the coupling portion (COUP) of the coupler or to the color developing agent. The ballast portion of the coupler remains immobile. In this type of coupler, the color of the difiusible dye is determined by the color of the reaction product of color developer oxidation product and the coupler moiety (COUP).

The following are representative DDR couplers used in the present invention, to Wit, nondiifusible coupler compounds that release or form ditfusible acid dyes on coupling with the oxidation products of color developing agents.

Couplers I to X below are substituted in the coupling position with preformed yellow dyes that are split from the ballasted couplers and become diifusible when said couplersreact with oxidized color developers.

(I) l-hydroxy- 4-{3-[4-(N-ethyl-B-sulfoethylamino)-2- methylphenylazo]phenylazo}-N-[6-(2,4-di-tert-amylphenoxy)butyl]-Z-naphthamide sodium salt.

(II) 1-hydroxy-4-{4-[1-(4 sulfophenyl)-3-methyl-4- pyrazol-S-onylazo -3 -sulfophenylazo}-N- B- (2,4-ditert-amylphenoxy)butyl]-2-naphthamide disodium salt.

(III) 1-hydroxy-4-{3-[4-(N-ethyl-N-B-carboxyethylamino)-2-methylphenylazo]phenylazo}-N-[5-(2,4-ditert-amylphenoxy)butyl]-2-naphthamide sodium salt.

(IV) l-hydroxy-4- (2,4-dinitrophenylthio -N- [6- (2,4-ditert-amyl-phenoxy butyl] -2-naphthamide.

(V) 1-hydroxy-4-{4- 1- (4-sulfophenyl) -3-methyl-4- pyrazol-S-onylazo]-3-sulfophenylazo}-N-{4-[or-(2,4- di-tert-amylphenoxy) butyramido] phenethyl}-2-naphthamide dipotassium salt.

(VI) 1-hydroxy-4-{4-[3-methyl-4-(1,5-disulfo-3-naphthylazo)-1-pyrazol-5-onyl]phenylazo}-N-{4-[or-(2,4-ditert-amylphenoxy)butyramido]phenethyl}-2-naphthamide dipotassium salt.

(VII) 1-hydroxy-4-{4-[3-methyl-4-(1,5-disu1fo-3- naphthylazo -1-pyrazol-5-onyl] phenylazo}-N- [6- (3 pentadecylphenoxy)butyl]-2-naphthamide disodium salt.

(VIII) 1- (p-t-butylphenoxyphenyl -3- [a- (4-t-butylphenoxy) propiouamido] -4- 2-bromo-4-methylamino- S sulfo-1-anthra-9,10-quinonylazo) -5-pyrazolone.

(IX) a-{ 3- a-( 2,4-di-tert-amylphenoxy acetamido] benZoyl}-u-{3- [4- (N-ethyl-N-fi-sulfoethylamino -2- methylphenylazo]phenylazo}-2-methoxyacetanilide sodium salt.

(X) 1-hydroxy-4{4- 1- (4-sulfophenyl -3-carboxy-4- pyrazol-5-onylazo] -3-sulfophenylazo}-N-{4- a- 2,4-ditert-amylphenoxy) butyramido] phenethyl}-2-naphthamide.

Each of the couplers XI to XLVI below contain an acid solubilizing group in a noncoupling position and on 6 coupling wth oxidized color developer forms a difiusible dye by the elimination of a ballasting group from the coupling position as a direct result of said coupling reaction.

Couplers XI to XXIX below form difl'usible cyan dyes.

(XI) 1-hydroxy-4-stearoyloxymercuri-2-naphthoic acid.

(XII) 1-hydroxy-4-dodecyloxy-Z-naphth-oic acid.

(XIII) l-hydroxy-4-(4-octadecyloxyphenylazo)-2- naphthoic acid.

(XIV) l-hydroxy-4-( 4-octadecyloxyphenylazo)-N 13'- (3,S-disulfobenzamido)ethyl] -2-naphthamide dipotassium salt.

(XV) 1-hydroxy-N-(fl-sulfoethyl)-4-(4-octadecyloxyphenylazo)-Z-naphthamide potassium salt.

(XVI) 1-hydroxy-4-(4-octadecyloxyphenylazo)-3- carboxy-4'-hydroXy-2-naphthanilide.

(XVII) 1-hydroxy-3',5'-dicarbomethoxy-4-dodecyloxy-2- naphthanilide.

(XVIII) 1-hydroxy-4-(2-hydroxy-4-pentadecylphenylazo) -N-ethyl-3 5 -dicarb oxy-2-n aphthanilide (XIX) 1-hydroxy-4-octadecyloxy-N-ethyl-3',5-

dicarboxy-Z-naphthanilide.

(XX) 1-hydroxy-4- 3-octadecylcarbamylphenylthio N-ethyl-3,5-dicarbOXy-Z-naphthanilide.

(XXI) 4,4-p-octadecyloxybenzylidenebis(l-hydroxy-N- ethyl-3 ,5 '-dicarboxy-Z-naphthanilide) (XXII) 1-hydroxy-5-acetamido-4-octadecyloxy-8- phenylazo-Z-naphthoic acid.

(XXIII) 2- 3,5 -disulfobenzamido) -5 -methyl-4- (4- octadecyloxyphenylazo) phenol dipotassium salt.

(XXIV) 2- 3,5 -disulfobenzamide) -4- 4-hydroxy-2-pentadecylphenylazo)-5-methylphenol dipotassium salt.

(XXV) 2- 3,5-dichlorosulfonylbenzamido) -5-methyl-4- (4-nitropheny1thio)phenol.

(XXVI) 1-hydroxy-4-(3-octadecylcarbamylphenylthio) N-methyl-N-(fi-carboxyethyl)-2-naphthamide.

(XXVII) l-hydroxy-4- 3-octadecylcarbamylphenylthio N-isopropyl-3',5 -dicarboxy-2-naphthanilide.

(XXVIII) 5-(3,5-disulfobenzamido)-4-(4-octadecyloxyphenylazo) 2-heptafiuorobutyramidophenol dipotassium salt.

(XXIX) 2,5 -bis( 3 ,5 -disulfobenzamido -4-(4-octadecyloxyphenylazo) phenol tetra potassium salt.

Couplers XXX to XLI below form dilfusible magenta dyes.

I (XXXVI) l-phenyl-3-(3,5-disulfobenzamido)-4-[4-(3- methyl-S-pentadecyl) pyrazolylazo] -5-pyrazolone dipotassium salt.

(XXXVII) 1- (4-sulfophenyl -3- (4-sulfoanilino -4- (2- hydroxy-4-pentadecylphenylazo) -5-pyrazolone dipotassium salt.

(XXXVIII) 1- 4-sulfophenyl -3- 4-sulfoanilino -4- (2- amino-4-pentadecylphenylazo)-5-pyrazolone dipotassium salt.

(XXXIX) l-[4-(3,5-dicarboxybenzamido)phenyl]-3 ethoxy-4-(3-octadecylcarbamylphenylthio)-5- pyrazolone.

(XL) 1-,(4 -sulfophenyl)-3-(4-sulfo.anilino)-4-(3- aniline, the following-colors of dye images were obtained octadecylcarbamylphenylthio)--pyrazolone on the reception layer from the respective couplers: disodium salt. Coupler:

(XLI) 4,4'-(4-octadecyloxybenzylldene)bis[l-phenyl- I Yellow 3-(3r5-disulfobenlamidwMyrazoloneltetm 5 1rIIIIIIIIIIIIII D6. potassium salt. In Couplers XLII to XLVI below form diffusible yellow IV ralnge-yellow.

dyes. V Yel OW.

(XLII) er-benzoyl-w(4-hydroxy-2-pentadecylphenylazo)- 10 zi g8 4-(3-sulfobenzamido) acetanilide sodium salt. VIII D (XLIII) a-benzoyl-u-(4-hydroxy-2pentadecylphenyl- IX azo)-4-(3,5-disulfobenzamido)acetanilide X dipotassiumsalt. XI Cyan (XLIV) u-benzoyl-u-[4-(3-metbyl-5-pentadecyl) XII o. pyrazolylazo] -4-(3,5-d1sulfobenzam1do) XIII D o acetanilide dipotassium salt. XIV

(XLV) a-benzoyl-u-(3-octadecylcarbamylphenylthio) XV D 3,iedicarboxyacetanilide. XVI D (XLVI) a-pivalyl-u-(3-octadecylcarbamylphenylthio)-4- XVH u D sulfoacetanilide potassium salt. XVIII D Diffusible dyes are formed-when the above listed (i.e., XIX Do.

I to XLVI) nondiffusing couplers are employed in the XX Do,

process of the invention with'well-known p-phenylenedi- XXI Do.

amine developing agents, e.g., N,N-diethyl-p-phenylenedi XII Do. amine, 2 amino S-diethylamino toluene, N-ethyl-B- XXIII Do. methanesulfonamidoethyl 3-methyl-4-aminoaniline, and XXIV Do. other N,N-d ialkyl-p-phenylenediamine developing agents XXV Do. described by Bent et al., J.A.C.S. 73, 3100-3125 (1951). XXVI Do Couplers XLVII toLV are nondiffusible couplers which XXVII Do can also beused in our invention when the color develop- XXVIII Do. ing agent is supplied with the alkali solubilizing function. XXIX Cyan.

Couplers XLVII to L below form diifusible cyan dyes. XXX Magenta.

(XLVI'I) 1-hydroXy-4-(4-octadecyloxyphenylazo)-N- i g methyl-Z-naphthanilide. XXXHI (XLVIII) 1-hydroxy-4-dodecylQXy-Z naphthanilide. XXXIV (XLIX) 1-hydroxy-4-(2 amino-4-octadecylphenylazoxy) XXXV Z-naphtharnide. XXXVI (L) 1-hydroxy-2,5-dibutoXy-4[4-(sulfomethyl) 40 XXXVH phenylazo] 2-naphthanilide. XXXVIH 3 Couplers L1 to LIII below form diffusible magenta XXXIX Db,

dyes. XL Do.

XLI Do. 2p; sg: y octadecyloxybenzyhdenel XLH Yellow (LII) 4,4-thiobis(1-phenyl-3-methyl-5-pyrazolone). XLHI (LIII) 4,4'-dithiobis(1-phenyl-3-methyl-5-pyrazolone). 3-

Couplers LIV and LN below form diffusible yellow XLVI 8: y XLVII Cyan.

(LIV) 61,06 (4 octadecyloxybenzylidene)bis[a-benzoyl- XLVHI acetanilide]. XLIX (LV) a,a*dithiObiSbel'lZOYltiCClfinilldE. 1:1 M

a enta. Representative color developing agents possessing the L11 solubilizing functions useful with the nonditfusing cou- 111 plers above are as follows: LI Yellow 4-amino-N-ethyl-3-rnethyl N-(B-sulfoethyl)aniline LV 4-arnino-N-ethyl-3-methoxy-N-( s-sulfoethyl)aniline The above-identified couplers have been described in 4-amino-N-ethyl-N-(B-hydroxyethyl)aniline the patent literature. Typical methods for preparing such 4-amino-N,N-diethyl-3-hydroxymethyl aniline couplers and related suitable couplers are described in the 4-amino-N-methyl-N-(B-carbOXyethyDaniIine following patents: 4-amino-N,N-bis(fi-hydroxyethynaniline 4-amino-N,N-bis(fi-hydroxyethyl)-3-methyl aniline $22332 $522523 gust 1960 a gust 2, 1960 3-acetam1do4-am1no-N,N-b1s(fl-hydroxyethyl)anrhne Great Britain 840 731 h d pu is e July 7, 1960 l?' Great Britain, 904,364, published August 29, 1962 antlme Sulfate Salt France, 1,224,012, delivered June 19, 1961 4'amm'NNd16thy1'3"(3'hydmxypropoxy)amhne France, 1,291,110, delivered March 12, 1962 When the DDR or dilfusible dye-releasing couplers France, 1,293,709, delivered April 9, 1962 given above were incorporated into exposed silver halide Belgium, 578,470, granted November 6, 1959 emulsionsthat were developed in contact with a mordant- Belgium, 591,444, granted June 30, 1960 ed reception layer using an alkaline color developing Belgium, 603,213, granted May 15, 1961 composition containing the aromatic primary amino color Belgium, 603,747, granted May 31, 1961 developing agent, 4 amino-N-ethyl-N-(B-hydroxyethyl) Belgium, 625,137, granted December 14, 1962.

The reductone derivatives used in the invention are amino hexose reductones and anhydro amino hexose reductones. Such compounds are derived from sugars, especially D-glucose, although other six carbon or hexose reducing sugars such as D-galactose, D-mannose, D-fructose, L-sorbose or the like can be used. A typical method for preparing the subject reductones comprises heating in a reaction medium substantially free of water a hexose reducing sugar and an aliphatic or cyclic secondary amine in the presence of an acidic reductone-forming catalytic agent such as phosphoric acid, boric acid, acetic acid, succinic acid or the like. The removal of three molecules of water results during the formation of the subject amino hexose reductones. The subject anhydro amino hexose reductones can be prepared by heating hydrochloride salts of the amino glucose reductones further in the presence of strong acids such as sulfuric acid, acetic anhydride zinc chloride and the like to remove another molecule of water. The amino moiety comprising the subject reductones can be represented by the following formula 2 RI \IT wherein:

R and R can be an alkyl radical, preferably having 1 to 8 carbon atoms, or together the necessary atoms to make a heterocyclic radical with the nitrogen atom,

preferably having a 5 or 6 atom nucleus and including a second nitrogen atom or any oxygen atom such as morpholino, piperazino, pyrrolino, pyridine, pyrimidino and the like.

These and other related suitable reductones and methods for preparing such are described in Hodges, U.S. Patent 2,936,308.

In accordance with the invention, the above-described reductone derivatives can either be incorporated in the developing or processing solution, in the photographic element, or in receiving sheets or layers that are used in conjunction with the light-sensitive elements during color development. The amount of reductone derivative utilized can be widely varied. When utilized in the processing solution amounts ranging from about .1 to 10 grams per liter are utilized. When the subject reductone derivatives are utilized in light-sensitive silver halide emulsion layers or layers contiguous thereto, or in receiving layers or sheets, about 1 to 100 milligrams of this addenda per mole of silver halide in the photographic element is typically used. When the subject reductone derivatives are used in layers, hydrophilic colloid layers are used.

The photographic elements of the invention are processed with aqueous alkaline compositions in the presence of an aromatic primary amino color developing agent, pphenylenediamine developing agents being particularly useful. The color developing agent can be either incorporated in an aqueous alkaline composition that is applied to the present photographic elements on processing 10 or the color developing agent can be incorporated in the light sensitive element.

The reception layer used to receive the diffused dye images on color development of the photoelements of the invention can be either a separate sheet pressed in contact with the phot-oelement or a layer integral with the photoelement.

When the reception layer is a separate reception sheet, the development and transfer operations can be effected by bathing either or both the exposed emulsion layer and a mordanted reception sheet in the aqueous alkaline processing solution before rolling into contact with each other. Alternately, a viscous processing composition can be placed between the elements for spreading in a predetermined amount across and in contact with the exposed surface of the sensitive element so as to provide all of the solution required for the picture area. The viscous processing composition is desirably utilized in one or more pods integral with the photoelement or the reception sheet that can be readily ruptured when development is desired, suitable viscous processing composition utilization techniques being disclosed in Land, US. Patents 2,559,643, 2,647,049, 2,661,293, 2,698,244, 2,- 698,798 and 2,774,668.

When the reception layer for receiving the ditfusible dye is an integral part of the photosensitive assembly, it is also useful. A typical element of this type can comprise a support, a mordanted colloid layer thereon and the various emulsion layers described above coated thereover. When easily dissolved emulsions are used such as those containing polyvinyl alcohol or an alkali-soluble cellulose ether phthalate vehicle, or a wet or dry stripping layer containing such vehicles is provided between the emulsions and reception layer, the developed emulsion layers can then be separated from the reception layer leaving the.dye image thereon. Similarly, the reception layer can be initially bonded to the outer emulsion surface. 'In this case, it is preferred to expose through the support of the sensitive element unless the reception layer itself is transparent. Such photoelements can be processed in the same manner as those not containing integral reception layers.

The reception layers in the photoelements of the invention can contain any of the conventional mordant materials for acid dyes. The reception layer can contain mordants such as polymers of amino guanidine derivatives of vinyl methyl ketone such as described in the Minsk US. Patent 2,882,156, granted April 14, 1959. Other mordants include the 2-vinyl pyridine polymer methop-toluene sulfonate and similar compounds described in Sprague et al. US. Patent 2,484,430, granted October 11, 1949, and cetyl trimethylammonium bromide, etc. Particularly efiective mordanting compositions are described in copen-ding applications of Knechel et al. US. Serial No. 211,095, filed July 19, 1962 now Patent No. 3,271,148 and Bush US. Serial No. 211,094, filed July 19, 1962 now Patent No. 3,271,147. The mordanting compositions described in the Knechel et al. application comprise at least one hydrophilic organic colloid containing a finely-divided, uniform dispersion of droplets or globules of a high-boiling, Water-immiscible organic solvent in which is dissolved a high concentration of a cationic, nonpolymeric, organic dye-mordanting compound for acid dyes. The mordanting compositions described in the Bush application comprise at least one hydrophilic organic colloid containing a finely-divided, uniform dispersion of particles of a salt of an organic acidic composition containing free acid moieties and a cationic, nonpolymeric, organic dye-mordanting compound for acid dyes. Useful cationic or basic organic dyemordanting compounds for acid dyes include quaternary ammonium and phosphonium, and ternary sulfonium compounds in whch there is linked to the N, P, or S onium atom at least one hydrophobic ballast group such as long-chain alkyl or substituted alkyl groups, Furthermore, the reception layer or sheet can be sutficient by it- 11 self to mordant the dye as in the case of use of a sheet or layer of a polyamide or related polymeric material.

Inpreparing the photographic elements of the invention, silver halide emulsions are preferably coated on photographic supports in the form of multilayer color photographic elements wherein at least three emulsion layers sensitive to different regions of the visible spec-v trum are coated on the. support. For example, the uppermost light-sensitive emulsion layer is generally selectively sensitive to blue'light, the next light-sensitive emulsion layer is generally selectively sensitive to green light, and the light-sensitive emulsion layer nearest the support is generally selectively sensitive to redlight. Between the blue and green sensitive emulsion layers there is typically disposed a Carey Lea filter layer for absorbing-blue radiation that may be transmitted through the uppermost blue sensitive layer. The red, greenand blue light-sensitive silver halide layers have contiguous .to the silver halide (e.g., incorporated in the emulsion or in adjacent layers) a cyan-forming, a magenta-forming and a yellowforming coupler respectively, so that dyes substantially complementary to the color sensitivities of the emulsions are formed on color development. However, the physical disposition of the red, green and blue light-sensitive silver halide layers within the present photographic elements can be widely varied in accordance with usual practice. Such multilayer photographic elements can also have other interlayers or sublayers for specialized purposes in accordance with usual practice.

In another embodiment of the invention, a single layer light-sensitive element could be utilized to prepare diffusion transfer full color images. Three types of packets of difierently sensitized silver halide emulsions and their corresponding couplers for subtractive color photography can be incorporated into a single emulsion layer on a photographic support. Reference is made to Godowsky US. Patent 2,698,794 for suitable'methods for preparing silver halide-color coupler packets.

The drawings illustrate in section and in elevation typical photographic elements of the invention.

FIG. 1 of the drawings illustrates a typical photographic element of the invention wherein the diffusi'ble dye-releasing or DDR coupler is positioned in light-sensitive emulsion layer 11 coated on support 10. Such an element is a single color elementand can be processed after exposure to prepare a direct positive color image by wetting the exposed element with an aqueous processing solution containing an aromatic primary amino developing agent and a reductone derivative of the invention. A receiving sheet having a reception layer which desirably contains a mordant is juxtaposed on light-sensitive emulsion layer 11 and the positive image formed when the diffusible dye-releasing coupler reacts with oxidized color developing agentis allowed to dififuse and be transferred to the receiving sheet. The reductone derivative of the invention could also be positioned in the receiving sheet or in a layer superposed on layer 11.

FIG. 2 illustrates a typical multicolor photographic element of the invention as well as a typical mordanted receiving sheet and a rupturable pod containing a processing composition that can be suitably utilized in conjunction with such photographic element. Coated on support is red-sensitive emulsion layer 21 which contains a nondiffusible coupler that forms a diffusible cyan dye when reacted with oxidized color developing agent. Over red-sensitive emulsion layer 21 is coated interlayer 22 that serves to separate green-sensitive emulsion layer 23 and red-sensitive emulsion layer 21. Interlayer 22 can contain such addenda as anti-oxidants, couplers to. form nondiffusible dyes with oxidized color developing agent from adjacent layers, filter dyes such as a magenta filter dye or the like. Green-sensitive emulsion layer 23 contains a nondiffusible coupler that forms a dilfusible magenta dye on color development. Over green-sensitive emulsion layer 23 is coated interlayer 24 that serves to separate green-sensitive emulsion layer 23 and blue-sensitive emulsion layer 25. Interl-ayer 24, like interlayer 22, can con-.

jacent layers, filter dyes and the like. Interlayer 24 typi-,

cally contains yellow Carey Lea silver to serve as a filter for blue light. Blue-sensitive emulsion layer 25 contains a nonditfusible coupler that forms a diffusible yellow dye on reaction with oxidized color developing agent. Over blue-sensitive emulson layer 25 is coated topcoat layer 26 that typically contains such addenda as antioxidants, ultraviolet absorbers and the like. In FIG. 2 is also illustrated a receiving sheet comprising support 28 having coated thereon mordant layer 27 and aflixed thereto rupturable pod 29 containing processing solution. Such processing solution is an aqueous alkaline material and can contain the reductone derivatives of the invention. Lightsensitive layers 21, 23 and 25 are direct positive silver halide emulsion layers wherein the silver halide grains have a substantial amount of sensitivity internalto the grains. When such emulsions are processed in the presence of a fogging agent such as the present reductone derivatives, they develop in positive image areas or unexposed areas. Accordingly, in the processing of an exposed photographic element of the type described ,in FIG.

2 of the drawings, development occurs in the unexposed areas and resulting oxidized color developing agent reacts with the color couplers in the respective red, green, and blue sensitive layers to form dilfusible cyan, magenta, and yellow dyes respectively. Such dyes diffuse imagewise to the surface of theiphotographic element and can be transferred to mordant layer 27 as positive color images.

The invention is illustrated by the following examples of preferred embodiments thereof. In the examples, DDR couplers are identified by the same Roman numerals used above.

EXAMPLE 1 A multilayer photographic element suitable for use in preparing three-color diffusion transfer images of the type illustrated by FIG. 2 of the drawings was prepared by coating on a cellulose acetate film support the following layers numbered in sequence from the support:

(1) Red-Sensitive Layer (e.g., Layer N0. 21, FIG. 2).-To one mole of a melted direct positive silver -bromoiodide emulsion that had been red-sensitized, was added 108 g. of cyan coupler XX in 2500 ml. of water and enough photographic gelatin to make a total of 139 g. per mole of silver halide. This solution was then coated so as to obtain 193 mg./ft. of gelatin, 150 mg./ft. of coupler, and 150 mg./ft. of silver.

(2) Interlayer (e.g., Layer No. 22, FIG. 2).-To 4540 g. of a 10% photographic gelatin solution was added 250 g. of the antioxidant, 2 octadecyl 4 sulfohydroquinone.

potassium salt, in 5000 ml. of hot water. This Was coated to obtain 91 mg./ft. of gelatin and 50 mg./ft. of the antioxidant.

(3) Green-Sensitive Layer (e.g., Layer No. 23, FIG. 2).--To one mole of a melted direct positive silver bromoiodide emulsion that had been green-sensitized, was added 81 g. of magenta coupler XXXVII in 3000 ml. of water and enough photographic gelatin to have a total of 162g. per mole of silver halide. This solution was coated so as to obtain 180 mg./tt. of gelatin, mg./ft. of coupler, and mg./ft. of silver.

(4) Interlayer (e.g., Layer N0. 24, FIG. 2).-To 4540 g. of 10% photographic gelatin solution was added 250 g. of the antioxidant used in layer 2 in 5000 ml. of hot water and 4.0 g. of yellow Carey Lea silver as a dispersion. This solution was then coated to obtain 91 mg./ft. of gelatin, 50 mg./ft. of antioxidant, and 8 ing/ft? of Carey Lea silver.

2).To one mole of a melted direct positive silver bromoiodide emulsion that was inherently blue lightsensitive, was added 144 g. of coupler XLVI that had been dissolved in 750 ml. of ethyl alcohol and 3000 ml. of water and enough photographic gelatin to have a total of 118 g. per mole of silver halide. This solution was coated so as to obtain 161 mg./ft. of gelatin, 200 Ing./ft. of coupler, and 150 mg./ft. of silver.

(6) Topcoat Layer (e.g., Layer N0. 26, FIG. 2).- To 4540 g. of a 10% photographic gelatin solution was added 250 g. of ultraviolet absorbing compound, -(4- 'methoxy 3-sulfo)-benzylidene-2-phenylimino-3-octylthiazolidone sodium salt in 5000 ml. of water. This solution was coated to obtain 91 mg./ft. of gelatin and 50 mg./ ft. of the ultraviolet absorbing compound.

' The silver bromoiodide emulsions utilized in layers 1, 3 and 5 (layers 21, 23 and 25 of FIG. 2) were of the type described in Davey et al, US. Patent 2,592,250 wherein the silver halide grains have high internal sensitivity and low surface sensitivity. Tests samples of the prepared photographic element were then exposed for second with a 500 watt positive lamp and a 4.08

the developing composition described below in the presence of various reductone derivatives of the invention, and positive dye images transferred to receiving sheets as described in Example 1. The color developing composition utilized had the following composition:

Color developing composition The D and D values of the transferred positive dye images resulting when the various reductone derivatives were utilized in the color developing composition are summarized by the data in Table 11 below.

TABLE II mux Dmin Reductone Derivative in the Developer Red Green Blue Red Green Blue (1) Piperidino hexose reductone 2. 38 2.38 2. 41 0.17 0.18 0. 24 (2) Diallylaminc hexose reductone. 2. 35 2. 2. 32 0. 18 0.20 0.26 (3) Piperazino (11(hexose reduct0ne). 2. 22 2.14 1.84 0.18 0.18 0.24 (4) Anhydro piperidino hexose reductone 2.22 2. 06 2.16 0.16 0.18 0.26 (5) Morpholino hexose reductone. .1 2.30 2. 22 2. 24 0.18 0.17 0.22

EXAMPLE 3 Corning filter on an Eastman Type IB intensity scale sensitometer, thereafter immersed in a color developing composition for 10 seconds and then pressed in contact with receiving sheets containing a cationic mordant for 5 minutes at 75 F. Thereafter the receiving sheets were removed and the dye densities of the positive images on the receiving sheets determined. The color developing composition had the following basic formulation, to which was added for purposes of comparison feature reductone derivatives of the invention at concentrations of 2.0 grams per liter of color developing composition:

A three-color light-sensitive element of the type described in Example 1 was prepared except that topcoat layer 6 (layers 26 of FIG. 2) contained the color developing agent and the reductone derivative. After exposure, the light-sensitive element Was developed by imbibing with an aqueous alkaline processing composition and positive images were transferred to a juxtaposed receiving sheet, such positive images having high D and low D values for all three colors. The topcoat layer was prepared by coating from the melt the following composition:

10% gelatin solution g 4540 Color developing composition 10% developer-reductone solution 1 g 9080 15% saponin cc 1000 2.72% mucochloric acid cc 45 Grams Water to make a total of g 59,000 s ium sulfite (desiccated) 2 g a lfl 523.25%3= 1) n 100 -{1II11D0-1 -e y 'u y' rox'ye y ani ue g sodlqm hydroxlde 20 Piperidino hexose reductone g 4-am1noN-ethyl-N-(,B-hydroxyethyl)aniline 20 gogium ls u1ite (desicclated) g 3 Waterw make 1 liten 11.55. 1 ififiliPi f 111:11:1111:11::11i2c:: 750 The results are summarized in Table I below. (pH adJusted to 6. 5 with 2 N sulfuric acid and final volume adjusted to 1000 cc. with water) TABLE I Dmax miu Reductone Derivative in the Developer Red Green Blue Red Green Blue (1) None 0. 75 0.38 0. 3e 0. 17 0.20 0. so (2) 'Dimethylamino hexose reductone 1 1.14 0.55 0. 40 0. 20 0.20 0.26 one 0. 95 0. 54. 0. 41 0.17 0.17 0. 23 (4) Piperidino hexose reductone 1. 37 0. 74 0. 62 0.15 0. 16 0.27

As can be observed from the data set out in Table I above, the reductone derivatives facilitated the reversal effect, substantially higher dye densities in the D areas for allcolors being obtained when the color development was effected in the presence of the reductone derivatives. EXAMPLE 2 Samples of three-color light-sensitive elements of the typedescribed in Example 1 were exposed, developed in The topcoat composition described above was coated to contain 200 mg. of Z-amino-N-ethyl-N-(,B-hydroxyethyD- aniline per square foot.

EXAMPLE 4 vention, the feature reductone derivatives also serve as stabilizing addenda for aromatic primary amino color developing agents. Ascorbic acid is also a stabilizer for such color developing agents, However, ascorbic acid undesirably reduces the toe speed of the cyan image in particular, the reductone derivatives of the invention not exhibiting this property in the present system. Several samples of the photographic element described in Example 1 were processed-in a developing composition of the type described in Example 1 containing varying amounts of piperidino hexose reductone and ascorbic acid. The relative toe speeds of the cyan scale (density 0.6) are summarized in Table III below.

The invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected Within the spirit and scope of the invention as described hereinabove andias defined in the appended claims.

I claim:

1. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a nondiffusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a dilfusible dye, forming a ditfusible dye in positive image areas, and transferring said diffusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of a reductone derivative selected from the group consisting of an amino hexose reductone and an anhydro amino hexose reductone wherein the amino moiety of said reductone derivative has the formula wherein R and R are selected from the group consisting of alkyl radicals and together with the nitrogen atom the necessary atoms to form a nitrogen-containing heterocyclic radical.

2. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a nondiffusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent toform a difiusible dye, forming a diffusible dye in positive image areas, and transferring said diffusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of piperidino hexose reductone.

3. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form prises carrying out said color developing in the presence of diallylamino hexose reductone.

4. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion.

layer having substantial proportions of silver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a nondiifusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diffusible dye, forming a diffusible dye in-positive image areas, and transferring said diffusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of piperazino hexose reductone.

5. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of siliver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a nondiffusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diffusible dye, forming a ditfusible dye :in positive image ,areas, and transferring said diffusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of anhydro piperidino hexose reductone.

6. In the color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a nonditfusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diffusible dye, forming a diffusible dye in-positive image areas, and transferring said difiusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of morpholino hexosereductonc.

7. In the. color developing with an alkaline developing composition containing an aromatic primary amino color developing agent of a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form latent images inside thesilverhalide grains, and having disposed integral with said element and contiguous to said emulsion a nondifi'usible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diffusible dye, forming a diffusible dye in positive image areas, and transferring said diflusible dye to a reception layer, the improvement which comprises carrying out said color developing in the presence of dimethylamino hexose reductone.

8. A color photographic diffusion transfer process which comprises exposing to a visible subject a photographic element comprising a support with superposed red, green and blue light-sensitive direct positive hydrophilic colloid silver halide emulsion layers wherein the silver halide forms latent images predominantly inside the silver halide grains and having disposed integral with said element and contiguous to said emulsions a cyan-forming coupler, a magenta-forming coupler and a yellow-forming coupler,

said couplers being nondifiusible during development in t (1) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a -pyrazolone coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nondiffusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of l to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

wetting said element with said alkaline color developing composition and developing said emulsions in the presence of a reductone derivative, said couplers coupling with oxidation product of said color developing agent during said color development and thereby cleaving said LINK in said couplers releasing difiusible acid dye images in areas of the said development, during the course of said color development said dye images diffusing imagewise in register to a juxtaposed reception layer containing a mordant for acid dyes and thereby producing a positive color reproduction of said subject, said reductone derivative being selected from the group consisting of an amino hexose reductone and an anhydro amino hexose reductone wherein the amino moiety has the formula wherein R and R are selected from the group consisting of alkyl radicals and together with the nitrogen atom the necessary atoms to make a heterocyclic radical.

9. The process of claim 8 wherein the reductone derivative is present in the alkaline color developing composition at a concentration of about .1 to 10 grams per liter of developing composition.

10. The process of claim 8 wherein the reductone derivative is present in a hydrophilic colloid layer on the emulsion side of the photographic element at a concentration of about 1 to 100 mg. per mole of silver halide in the photographic element.

11. A color photographic difiusion transfer process which comprises exposing to a visible subject a photographic element comprising a support with superposed red, green and blue light-sensitive direct positive gelatinosilver halide emulsion layers wherein the silver halide forms latent images predominantly inside the silver halide grains and having disposed integral with said element and contiguous to said emulsions a cyan-forming coupler, a magenta-forming coupler and a yellow-forming coupler, said couplers being nondiflusible during development in the presence of an alkaline color developing composition containing an aromatic primary amino color developing agent, capable of forming diffusible acid dyes substantially complementary to the color of the spectral sensitivity of the respective contiguous light-sensitive layers in said alkaline color developing solution by reaction with color development oxidation product of said color developing agent and having a formula selected from the group consisting of DYELINK(COUPBALL) and BALLLINK(COUPS 0L) wherein:

(1) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nondiffusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of l to 2 when said LINK is an alkylidene radical, and n is 1 When said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

Wetting said element with said alkaline color developing composition and developing said emulsions in the presence of a dialkylamino hexose reductone wherein the alkyl radicals have 1 to 8 carbon atoms, said couplers coupling with oxidation product of said color developing agent during said color development and thereby cleaving said LINK in said couplers releasing diffusible acid dye images in areas of the said development, during the course of said color development said dye images dilfusing imagewise in register to a juxtaposed reception layer containing a mordant for acid dyes and thereby producing a positive color reproduction of said subject.

12. A color photographic diffusion transfer process which comprises exposing to a visible subject a photo graphic element comprising a support with superposed red, green and blue light-sensitive direct positive gelatinosilver halide emulsion layers where in the silver halide forms latent images predominantly inside the silver halide grains and having disposed integral with said element and contiguous to said emulsions a cyan-forming coupler, a magenta-forming coupler and a yellow-forming coupler, said couplers being nondiffusible during development in the presence of an alkaline color developing composition containing an aromatic primary amino color developing agent, capable of forming ditfusible acid dyes substan tially complementary to the color of the spectral sensitivity of the respective contiguous light-sensitive layers in said alkaline color developing solution by reaction with color development oxidation product of said color devel- 1 9 oping agent and having a formula selected from the group consisting of DYELlNK(COUP-BALL) and BALL LINK(COUPSOL) wherein:

(1) DYE' is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;'

(3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a phenolic coupler radical and an open-chain ketomethylene, coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nondiffusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and (6) n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when saidLINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical; wetting said element with said alkaline color developing composition and developing said emulsions in the presence of an amino hexose reductone wherein the amino moiety is a monovalent nitrogen-containing heterocyclic radical having 5 to 6 atoms, said couplers coupling with oxidation product of said color developing agent during said color development and thereby cleaving said LINK in said couplers releasing dilfusible acid dye images in areas of the said development, during the course of said color development said dye images diffusing imagewise in register to a juxtaposed reception layer containing a mordant for acid dyes and thereby producing a positive color reproduction of said subject.

13. In atphotographic element comprising a support and a direct positive silver halide emulsion layer havin substantial proportions of silver halide that form latent images inside the silver halide, grains, and having disposed integral with said element and contiguous to said emulsion a nondifiusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diffusible dye, the improvement which comprises having a layer on the emulsion side of said element containing a reductone derivative selected from the group consisting of an amino hexose reductone and an anhydro amino hexose reductone wherein the amino moiety of said reductone derivative has the formula wherein R and R are selected from the group consisting of alkyl radicals and together with the nitrogen atom the necessary atoms to form a nitrogen-containing hetero cyclic radical.

14. In a photographic element comprising a support and a direct positive silver halide emulsion layer having substantial proportions of silver halide that form latent images inside the silver halide grains, and having disposed integral with said element and contiguous to said emulsion a ,nonditfusible photographic color coupler that reacts with oxidized aromatic primary amino color developing agent to form a diifusible dye, the improvement which comprises having a layer on the emulsion side of which comprises having, a layer on the emulsion side of said element containing an amino hexose reductone Wherein the amino moiety is a monovalent nitrogen-contam1ng heterocyclic radical having 5 to 6 carbon atoms.

16. A photographic element comprising a support with superposed red, green and blue light-sensitive direct positive hydrophilic colloid silver halide emulsion layers wherein the silver halide forms latent images predominantly inside the silver halide grains, a hydrophilic colloid layer on the same side of said support as said emulsion layers containing a reductone derivative selected from the group consisting of an amino hexose reductone and an anhydro amino hexosereductone wherein the amino moiety of said reductone derivative has the formula wherein R and R are selected from the group consisting of alkyl radicals and together with the nitrogen atom the necessary atoms to form a nitrogen-containing heterocyclic radical, and disposed integral with said element and contiguous to said emulsions a cyan-forming coupler, a magenta-forming coupler and a yellow-forming coupler, said couplers being nonditfusible during development in the presence of an alkaline color developing solution containing an aromatic primary amino color developing agent, capable of forming diffusible acid dyes complementary to the color of the spectral sensitivity of the respective contiguous light-sensitive emulsions in the presence of said alkalinecolor developing solution by reaction with color development oxidation product of said color developing agent and having a formula selected from the group consisting of DYELINK(COUPBALL) and BALL-LINK--(COUP---SOL) wherein:

(1) DYE is a dye radicalexhibiting selective absorptionin the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nonditfusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 when LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical.

17. A photographic element comprising a support with superposed red, green and blue light-sensitive direct positive gelatino-silver halide emulsion layers wherein the silver halide forms latent images predominantly inside the silver halide grains, a gelatin layer on the same side of said support as said emulsion layers containing a dialkylamino hexose reductone wherein the alkyl moiety has 1 to 8 carbon atoms, and disposed integral with said element and contiguous to said emulsions a cyan-forming coupler, a magneta-forming coupler and a yellow-forming coupler, said couplers being nonditfusible during development in the presence of an alkaline color developing solution containing an aromatic primary amino color developing agent, capable of forming difi'usible acid dyes substantially complementary to the color of the spectral sensitivity of the respective contiguous light-sensitive emulsions in the presence of said alkaline color developing solution by reaction with color development oxidation product of said color developing agent and having a formula selected from the group consisting of DYELINK(COUPBALL) and BALIPLINK(COUPSOL) wherein (1) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

( 3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nondifiusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 When said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical.

18. A photographic element comprising a support With superposed red, green and blue light-sensitive direct positive gelatino-silver halide emulsion layers wherein the silver halide forms latent images predominantly inside the silver halide grains, a gelatin layer on the same side of said support as said emulsion layers containing an amino hexose reductone wherein the amino moiety is a monovalent nitrogen-containing heterocyclic radical having 5 to 6 atoms, and disposed integral With said element and contiguous to said emulsions a cyan-forming coupler, a magnetic-forming coupler and a yellow-forming coupler,

said couplers being nondiflusible during development in the presence of an alkaline color developing solution ntaining an aromatic primary amino color developing agent, capable of forming difiusible acid dyes substantially complementary to the color of the spectral sensitivity of the respective contiguous light-sensitive emulsions in the presence of said alkaline color developing solution by reaction with color development oxidation product of said color developing agent and having a formula selected from the group consisting of DYE-LINK- COUP---BALL) and BALL-LINK( COUPSOL) wherein:

(1) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a 5-pyrazol0ne coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said couplers nondiffusible during development in said alkaline color developing solution;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing grou when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 When said LINK is an alkylidene radical, and n is 1 When said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical.

19. A photographic element as described in claim 17 wherein the dialkylamino hexose reductone is dimethylamino hexose reductone at a concentration of about 1 to mg. per mole of silver halide in the emulsions of the photographic element.

20. A photographic element as described in claim 18 wherein the amino hexose reductone is piperidino hexose reductone at a concentration of about 1 to 100 mg. per mole of silver halide in the emulsions of the photographic element.

References Cited UNITED STATES PATENTS 2,588,982 3/1952 Ives 96-64 2,936,308 5/1960 Hodge 96-66 3,227,550 1/1966 Whitmore 96-3 3,227,554 l/1966 Barr et al. 96- 3,:

J. TRAVIS BROWN, Primary Examiner, 

8. A COLOR PHOTOGRAPHIC DIFFUSION TRANSFER PROCESS WHICH COMPRISES EXPOSING TO A VISIBLE SUBJECT A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT WITH SUPERPOSED RED, GREEN AND BLUE LIGHT-SENSITIVE DIRECT POSITIVE HYDROPHILIC COLLOID SILVER HALIDE EMULSION LAYERS WHEREIN THE SILVER HALIDE FORMS LATENT IMAGES PREDOMINANTLY INSIDE THE SILVER HALIDE GRAINS AND HAVING DISPOSED INTEGRAL WITH SAID ELEMENT AND CONTIGUOUS TO SAID EMULSIONS A CYAN-FORMING COUPLER, A MAGENTA-FORMING COUPLER AND A YELLOW-FORMING COUPLER, SAID COUPLERS BEING NONDIFFUSIBLE DURING DEVELOPMENT IN THE PRESENCE OF AN ALKALINE COLOR DEVELOPING COMPOSITION CONTAINING AN AROMATIC PRIMARY AMINO COLOR DEVELOPING AGENT, CAPABLE OF FORMING DIFFUSIBLE ACID DYES SUBSTANTIALLY COMPLEMENTARY TO THE COLOR OF THE SPECTRAL SENSITIVITY OF THE RESPECTIVE CONTIGUOUS LIGHT-SENSITIVE LAYERS IN SAID ALKALINE COLOR DEVELOPING COMPOSITION BY REACTION WITH COLOR DEVELOPMENT OXIDATION PRODUCT OF SAID COLOR DEVELOPING AGENT AND HAVING A FORMULA SELECTED FROM THE GROUP CONSISTING OF 